Multistage suction fan for vacuum cleaners and the like



May 12, 192s. 1,537,732

H. BAUMEISTER A MULTISTAGE SUCTION FAN FOR VACUUM CLEANERS AND' THE LIKE Filed May 1e, 192s fn Ven or.: v Heinrich Baume/sen ily qw His Aorney Patented May 12, 1925.

UNITED STATES HEINRICH BAUMEISTER, 0F kIEANKOV, GERMANY, ASSIG-NOR TO GENERAL ELECTRIC PATENT OFFICE.

COMPANY, A CORPORATION OF NEW YORK.-

MULTISTAGE SUCTION FAN FOR VACUUM CLEANERS AND THE IIKE.

Application filed May 18, 1923. Serial No. 639,765.

To @ZZ whom t may concern.'

Be it known that I, HEINRICH BAUMEIS- TER, a citizen of the German Realm, ree `siding at Pankow, Germany, have invented certain new and useful Improvements in.

' multistage suction-producing fan of this type.

For a consideration of what I believe to be novel and my invention, attention is directed to the `following specification and the claims appended thereto.

In the drawing, Fig. l is a vertical, sectional View of a suction cleaner equipped with a suction fan or suction-producing mechanism embodying my invention: Fig. 2 is a sectional view through the suctionproducing device: Fig. 8 is a transverse, sectional view, and Fig. l is a diagrammatic, perspective view illustrating the path` of the air as it flows through the multi-stage fan.

Referring to the drawing, the vane wheel 'a provided with a vane b rotates between two stationary drums c and (l. The vane wheel a with the vane o thereon forms a suction lan and it is shown as being connected to the shaft of an electric motor n by which it is driven. `he inner drum c is divided by the partition e into two chambers f and g. The two drums c and d are attached directlyto a wall w of the casing of the suction cleaner. The chamber f is the admission chamber to the fan and communicates through an opening It in the wall fw with the region from which the air is to be drawn. In the present instance, this is the chamber 5 located beneath the filter plate m of the vacuum cleaner. The drum c is provided with a recess through which the air which has been drawn up can pass into the vane wheel. Air is discharged from the vane wheel through a recess 7c in the outer drum vinto the hollow space Z which is formed by a cylinder or casing wall m and is bound ed by the partition walls n, n. From this space the ,air passes through an opening c in the wall fw into a passage p which is formed by a sheet metal cap Q and opens through an opening r into the chamber ,f/ in the inner passes through the opening s for the second time into the vane wheelv and is dis charged therefrom through the opening s into an outer chamber t whence it'escapes through a discharge opening n into the open air. By `this arrangement it will be seen that the air is acted upontwice by the impeller thereby obtaining the eii'e-ct of a drum. From here the air (itl multi-stage apparatus. By this means I am enabled with a single impeller to obtain a much greater suction than has heretofore been possible and at the same time utilize a lower speed for the revolving fan. In vacuum cleaners having only a single vstage fan the speed of the motor must be relatively high in order to produce sufficient suction for eic-ient cleaning and this is ob` `gectionablel on account of thel difficulties in manufacturing and keeping in operative condition a high speed apparatus. By my invention I am enabled to obtain equally good resultswith a much lower speed motor.

It will be noted that the piece of sheetv lmetal g which divides the passage p is located inside the vacuum cleaner casing so that it does not take up any outside space. It may `with advantage also serve as a sup-- port for the lilter w.

Inv the present invention I have shown a two-stage arrangement, that is, one in which the air is acted upon by the impeller twice in passing from charge opening. I may, however, in a similar manner provide more found desirable. i

In Fig. l, 6 and 7 indicate the handles of the vacuum cleaner, 8 the suction nozzle and 9 the casing which is divided by the lilter member' In operation, the suction nozzle is moved over the surface to be cleaned in theusual manner, the dust-laden air being drawn through the nozzle into the cleaner casing. I-Iere the air passes through the filter m which may be formed of cloth or other suitable material while the particles of dust are caught by the filter and retained in the casing.

It will be understood, of course, that the particular type of cleaner with which my invention-is shown is illustrated only by way ot example and that the invention may be the inlet opening to the disl than two stages it' embodied in connection With any suitable type of vacuum cleaner. It will also be understood that such a mechanism embodying my invention may be used in connection with any apparatus or for any purposes to which it may be found applicable.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understocd that the ap paratus shown is'only illustrative and that the invent-ion may be carried out by other means.

lliat I claim as new and desire to secure by Letters Patent of the United States, is

1. In an apparatus 0I' the character described, the combination of a casing having an inlet opening and aii outlet opening, an impeller in the casing, a wali which surrounds the impeller in spaced relation to the casing, said wall having openings which communicate with the periphery of theA iin-v peller at spaced points, partition means between said wall and casing providing a discharge chamber for each wall opening, means providing a plurality of inlet chambers for said impeller, and walls which des line a passage connecting one` of said outlet chambers to one of the inlet chambers.

9.. In an apparatus of the character described, the combination 0I' a. casing having an inlet openingL and a discharge, opening,

walls forming a pair of spaced drums in thecasing, a suction I'an having vanes which revolve between said drums, and partition walls and passa-ges in said drums for directling the medium being pumped to and from vsaid vanes a plurality of times in flowing peller having vanes which revolve between said inner wall and the outer walls, said walls having passages for directing medium being pumped from the admission chamber a plurality of times through the impeller to the outlet chamber.

4. In an apparatus of the character described, an impeller wheel having vanes thereon, an. inner annular wall havingy par tition means therein to form a plurality of chambers which communicate with the admission sides O the vanes at different points, an outer annular wall in spaced relation to the casing, partition means between said last named wall andthe casing which'iiorins -therewith a plurality of chambers v which .communicate with the discharge sides ot' the vanes at different points, and a wall which Iornis a passage connecting an inlet chain-` ber to anoutlet chamber.

In witness whereof, I have hereunto set my hand this 28th day of April, 1923.

HEINRICH BAUMEISTER. 

